[baq]

average is an average, you're forgetting about extremes.

it only takes a few days (or hours) of above wet bulb temperatures to kill humans who live in and around the tropics today.

https://en.wikipedia.org/wiki/Wet-bulb_temperature

[trashtester]

So people will move out of those worst affected areas.

[baq]

Exactly. Hundreds of millions of them.

[trashtester]

Sure. That could happen. Or there could be wars/conflicts resulting in some of those not having anywhere to go.

Still, this scenario is quite different from human extinction, which is what I was responding to further up.